P00B7 code meaning
Engine Coolant Flow Low/Performance
Powertrain system Generic code P00xx codes Check engine light
What P00B7 means
When the engine is hot, the thermostat should be open and coolant should flow through the radiator. P00B7 is set when the engine coolant temperature is very high (above about 117 to 119 °C in documented cases) while the radiator side stays much colder, so too little coolant flows through the radiator. The usual cause is a thermostat stuck closed; low coolant, air in the system, a pump that delivers too little or a blocked radiator have the same effect. If the temperature keeps rising, stop driving to avoid engine damage.
P00B7 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor1 to 4 hours
- Clears after repairAfter a drive cycle
Symptoms of P00B7
- Check engine light on
- Coolant warning light
- High engine temperature up to overheating
- Weak or fluctuating cabin heating
Common causes of P00B7
- Most likelyThermostat stuck closed
- Most likelyLow coolant level or air in the cooling system
- PossibleCoolant pump delivering too little (impeller, drive; known cases on some engines)
- PossibleRadiator or hoses blocked
- Less likelyOne of the temperature sensors reading wrong
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
ThermostatCoolant pumpRadiatorEngine coolantRadiator coolant temperature sensor
What each part of P00B7 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 0 | Area: fuel and air metering and auxiliary emission controls. |
| B7 | The exact fault in that area. |
What to do next
- Note P00B7 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P00B7
What does P00B7 mean?
P00B7 means "Engine Coolant Flow Low/Performance". When the engine is hot, the thermostat should be open and coolant should flow through the radiator. It is a generic code, so it means the same on every make.
Is it safe to drive with P00B7?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P00B7 fail an emissions test?
Yes, it can. P00B7 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P00B7 to fix?
Difficulty: medium. A typical repair takes 1 to 4 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P00B7 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.